For many years, it has been known to dispense liquids, such as soaps, sanitizers, cleansers, disinfectants, and the like from a dispenser housing maintaining a refill unit that holds the liquid and provides the pump mechanisms for dispensing the liquid. The pump mechanism employed with such dispensers has typically been a liquid pump, simply emitting a predetermined quantity of the liquid upon movement of an actuator. Recently, for purposes of effectiveness and economy, it has become desirable to dispense the liquids in the form of foam, generated by the interjection of air into the liquid. Accordingly, the standard liquid pump has given way to a foam generating pump, which necessarily requires means for combining the air and liquid in such a manner as to generate the desired foam.
Typically, foam pumps include an air pump portion and a fluid pump portion—the two requiring communication to ultimately create the foam. Such pumps have been provided through various types of pump structures, as known by those familiar with the foam pump arts. In the prior art pumps, the fluid and air are often advanced through separate pathways that join adjacent a screen element, such that the separate air and fluid paths are brought together and then forced through the screen to create bubbles of air in the fluid, thus creating the foam. Generally, richer, higher quality foams are a result of having smaller bubbles with a more uniformly distribution of bubble sizes. This invention provides a particularly compact foam pump of a structure heretofore unknown in the art. This invention also provides a high quality foam with small and uniformly sized bubbles of air.